Not support downloading local markdown file

[jingping-ye]

Describe the bug

I placed a project.md file in the public directory and want to link it in my markdown file to download it. I tried using the following markdown syntax:

[markdown file | download](/project.md){target="_self" download}

However, after compilation, I noticed that the resulting HTML link was:

<a href="/project.html" target="_self" download="">markdown file | download</a>

So, it seems that the link I set in my markdown page becomes an HTML page.

Reproduction

Just see the "Describe the bug".

Expected behavior

After compilation, the result should be as follows:

<a href="/project.md" target="_self" download="">markdown file | download</a>

System Info

System:
    OS: macOS 14.5
    CPU: (8) arm64 Apple M1
    Memory: 112.03 MB / 16.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.12.2 - /usr/local/bin/node
    npm: 10.5.0 - /usr/local/bin/npm
  Browsers:
    Chrome: 125.0.6422.142
    Safari: 17.5
  npmPackages:
    vitepress: ^1.2.3 => 1.2.3

Additional context

No response

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